The present invention relates to a digital map display zooming method, a digital map display zooming device and a storage medium for storing a digital map display zooming program, which are for enlarging and reducing a displayed portion of a digital map as map information in digital form within a display screen.
Digital maps as map information in digital form are maps put into electronic form so as to be handled on the display screen of a computer as a digital map display device such as a portable notebook type computer etc. This kind of digital map is referred to as an electronic map or map software, where maps can be displayed on a display screen.
With this kind of digital map, a map is displayed on, for example, the display screen of a portable computer so that such an operation that a target is set on the map can be carried out, with these digital maps being applied to car navigation systems etc. in recent years.
Incidentally, the digital map display device has a function for zooming the displayed region of this kind of digital map. With digital map display devices in related art, a user can enlarge or reduce in a plurality of steps using a mouse as a pointing device. This situation is shown in FIG. 1. In FIG. 1, zooming in or zooming out can be carried out in a discontinuous manner within a range of about five steps on scales of 1000, 1001, 1002, 1003 and 1004. The area for which this enlarged or reduced displaying is to be performed can be designated by the direction of dragging the mouse. A xe2x80x9cmousexe2x80x9d is a device that can be moved about on a desk so as to designate a specific portion on a screen by pushing a mouse button with a pointer being positioned at the portion. xe2x80x9cDraggingxe2x80x9d is the action of moving the mouse with the mouse button pushed down.
However, a displayed portion of the digital map can only be enlarged or reduced in a discontinuous manner in a plurality of steps and it is therefore impossible to display an enlarged or reduced displayed portion at the display screen on a scale desired by the user.
It is therefore an object of the present invention to provide a digital map display zooming method, a digital map zooming display device and a storage medium for storing a digital map display zooming program that enable a user to enlarge or reduce a displayed portion of a digital map in a continuous manner within a display screen by solving the above problem.
The above object is achieved in the present invention by a digital map display zooming method for enlarging and reducing a displayed portion of a digital map as map information in digital form within a display screen of a display device with a pointing device, wherein operations of the first designating part and the second designating part of the pointing device designate continuous enlarging and continuous reducing of the displayed portion of the digital map within the display screen, respectively.
In the present invention, continuously enlarging operation and continuously reducing operation of the displayed portion of the digital map within the display screen can be designated by the operations of the first designating part and second designating part of the pointing device, respectively.
As a result, the user can continuously enlarge or continuously reduce the displayed portion of the digital map within the display screen in a simple manner.
The above object is achieved in the present invention by a digital map display zooming device for enlarging and reducing a displayed portion of a digital map as map information in digital form within a display screen, the device comprising a display section having a display screen for displaying the displayed portion of the digital map, a pointing device, having the first designating part and the second designating part, for continuously enlarging or reducing the displayed portion of the digital map within the display screen by operating the first designating part and the second designating part, respectively, and an arithmetic processor for carrying out processing for performing continuously enlarging operation and continuously reducing operation of a displayed portion designated by operations of the pointing device.
In the present invention, the displayed portion of the digital map is displayed at the display screen of the display section. The pointing device has the first designating part and the second designating part and continuously enlarging operation and continuously reducing operation of the displayed portion of the digital map are carried out within the display screen by. the user operating the first and second designating parts.
The arithmetic processor carries out processing for continuously enlarging operation and continuously reducing operation of the displayed portion designated by operating the pointing device.
In the present invention it is preferable that continuously enlarging operation of the displayed portion can be continued when the first designating part of the pointing device is kept being pressed and continuously reducing operation of the displayed portion can be continued when the second designating part of the pointing device is kept being pressed.
The user can therefore continuously enlarge or continuously reduce the displayed portion of the digital map within the display screen in a simple manner. Moreover, the user can carry out the required enlargement or reduction in a simple manner only by continuing pressing.
The above object is achieved in the present invention by a storage medium for storing a digital map display zooming program for enlarging and reducing a displayed portion of a digital map as map information in digital form within a display screen of a display device with a pointing device, wherein the digital map zooming program includes the steps of designating continuously enlarging operation and continuously reducing operation of the displayed portion of the digital map within the display screen by operations of the first designating part and the second designating part of the pointing device, respectively.
In the present invention, continuously enlarging operation and continuously reducing operation of the displayed portion of the digital map within the display screen can be designated by the operations of the first designating part and the second designating part of the pointing device, respectively.
As a result, the user can continuously enlarge or continuously reduce the displayed portion of the digital map within the display screen in a simple manner.